Well scratcher



Dec. 25, 1962 J. R. soLUM ETAL 3,070,168

WELL scRATcHER Filed April 2l, 1960 3 SheSS-Sheet 2 /WE'S Q. @LU/W V a//anv/c. #514051. 7 JNVENTORS DeC- 25, 1962 J. R. soLUM ETAL 3,070,168

WELL SCRATCHER Filed April 21, 1960 3 Sheets-Sheet S United States Patent Office Eiddbd Fatented Der:e 25, 1962 3,670,163 WELL SCRATEHER .lames R. Salam, Los Angeles, and William C. Hempel,

Manhattan Beach, Calif., assignors, by mesne assignments, to B W incorporated, Torrance, alif., a corporation of California Filed Apr. 2l, Hdd, Ser. No. 23,6% 10 Claims. (fil. 166-173) This invention relates to well scratchers of the general type shown in the Wright Patent 2,506,405.

The principal object of this invention is to provide a new and improved mounting for scratcher finger assemblies on the outer surface of the carrier. The carrier may comprise a cylindrical collar adapted to encircle the well pipe or may comprise an axially extending member adapted to be fixed on the outer surface of the well pipe. The collar type may be of solid cylindrical form or may be hinged if desired for lateral application to the well pipe.

A more particular object of this invention is to provide a well scratcher device having a plurality of retainers for clamping a foot piece of each scratcher finger assembly to the outer surface ot' the carrier, each retainer comprising a strip of metal sheared on parallel edges from the carrier and deformed outward therefrom to form two loops at spaced locations. The ends of each such strip remain integrally joined to the carrier and the central portion thereof is clamped between the edges of the opening of the carrier resulting from formation of the strip, each of the loops encompassing one of spaced parts provided on each foot piece.

Another object is to provide a scratcher device of the type described which is particularly well suited for economical manufacture on a quantity production basis.

Other and more detailed objects and advantages will appear hereinafter.

ln the drawings:

FlGURE 1 is a plan View showing a preferred embodiment of this invention.

FIGURE 2 is a side elevation thereof, the scratcher fingers being roken off for clarity of illustration.

FIGURE 3 is a sectional elevation taken substantially on the lines 3-3 as shown in FIGURE 2.

FIGURE 4 is a sectional detail taken substantially on the lines 4 4 as shown in FIGURE 2.

FIGURE 5 is a plan View showing a modified form of my invention.

FiGURE 6 is a side elevation showing a further modification.

FIGURE 7 is a sectional detail taken substantially on lines 7--7 as shown in FIGURE 6.

FlGURE 8 is a fragmentary side elevation of a portion of the device shown in FIGURE 2.

FIGURES 9, l0, and 1l are views similar to FIG- URE 8 showing modifications.

Referring to the drawings7 the carrier generally designated .ft-7, comprises a cylindrical collar lf defined by cooperating halves l2 and t3 which are substantial duplicates. Aligned hinge elements le and l5 at the ends of the collar halves are connected by hinge pins lo and f7. Either one of these hinge pins may be axially removed so that the collar halves may be opened up to permit lateral application to a well pipe. The pin is then reinserted into position and secured by any convenient means (not shown).

A circumferential series of scratcher finger assemblies 2t) is mounted on the outer surface 2l of the collar il. Each of the scratcher finger assemblies is formed from a single continuous length of wire. Each assembly 2t) includes a pair of scratcher fingers 22 extending from a coil 23, Zd. The coils have parallel axes and are of opposite lead. The supporting legs 25, 26 extend from one end of each coil respectively. These supporting legs are symmetrically positioned with respect to the scratchcr lingers 22 and are axially aligned.

A foot piece generally designated 27 joins the support legs and rests on the outer surface of the carrier. The foot piece includes spaced parallel parts 28 joined by a curved connector 29.

A series of retainers 3f) are provided on the collar 1l, one for each scratcher finger assembly respectively. Each of these retainers comprises a strip of metal slieared on parallel edges from the collar il and deformed ontward therefrom to form two loops 3l. The ends of each retainer strip remain integrally joined to the collar 1f and the central portion 32 thereof is clamped between the edges of the opening 33. This opening 33 is produced in the collar il by formation of the .retainer strip 30. Each of the loops 3l encompasses one of the spaced parts 23 of the foot piece 27 and thereby serve to clamp the foot piece rmly to the outer Surface of the collar il.

The retainer strip is first blanlzed from the collar 11 and assumes the single arch shape shown at 35 in FIG- URE 8. The foot piece Z7 of a scratcher finger assembly is then inserted under this arched strip on the outer surface of the collar lll.. The single arch 35 is then deformed to cause the central portion thereof to reenter the opening 33 defined by the parallel edges and the reverse curve 32- of the central portion is wedged tightly between the parallel Walls which define the opening 33. Considerable force is required to reinsert the central portion 32 between the walls of the opening 33 and the portion 32 is thus clamped tightly under compression.

Circumferentially extending protector ribs 38 are provided on the collar halves as shown in FGURES 14, and similar continuous protector ribs 39 are provided on that form of the device shown in FIGURE 5. The collar a as shown in FIGURE 5 is formed from a single metal strip with the ends joined at 46 to form a single endless ring. The mounting of the scratcher finger assemblies 2da is identical to that described above.

In that form of the invention shown in FIGURES 6 and 7 the carrier takes the form of a longitudinal member 1lb adapted to be fixed to the outer surface or a well pipe by welding d2. The scratcher finger assemblies 29h extend in a longitudinal series on the member 1lb and are mounted in the manner described above. Each of the retainers 3de extends in a longitudinal direction. A protector rib 39h extends continuously along one side of the member lib and a smaller rib 43 extends along the other side of the member 1lb. The ribs provide protection for the coil springs of the assemblies E-tlb, and the longitudinal rib 43 is relatively small to avoid interference with flexing action of the scratcher fingers.

FIGURES 9, l0 and 11 show modifications in the mounting of the scratcher linger assemblies on the carrier, and any of these may be employed on the types of carriers shown in FIGURES 1 4, FiGURE 5, and FIGURES 6, 7. in FIGURE 9 the spaced parts 28e are not parallel but converge in a direction opposite to the projection of the scratcher fingers 22C from the coils 23C. The central portion 32C of the retainer Eile is clamped under lateral compression as described above.

in FiGURE l0 the supporting legs 25d are axially aligned but the foot piece 27d does not have any parts which are parallel. instead, the foot piece is provided with concave curved parts 2da' joined by convex curved connector 29a'.

In FIGURE 11 the offset foot piece 27e projects in the same direction as the projection of the scrat-cher fingers 22e from the coils 23e, and the spaced parts 23e are not parallel but converge at an angle.

In each of the forms of the invention described above, the retainers are cut and formed in punch press operations witho-ut requiring any welding, and the number of separate parts is reduced to a minimum. These features are important because they make it possible to produce the device economically on a quantity production basis.

Having fully described our invention, it is to be understood that we do not wish to be limited to the details set forth above, but our invention is of the full scope of the appended claims.

We claim:

1. In a well bore cleaning scratcher, the combination of: a metallic carrier adapted to be mounted upon a wcll pipe, a series of scratcher finger assemblies mounted upon the carrier, each of the assemblies including a pair of coils, each coil having a scratcher finger projecting from one end thereof and a Support leg projecting from the other end thereof, an offset foot piece joining said support legs, each foot piece having spaced parts joined by a connector, a plurality of retainers on the carrier, one for each scratcher finger assembly, each retainer comprising a strip of metal sheared on two edges from the carrier and deformed outward therefrom to form two loops at spaced locations, the ends of each strip remaining integrally joined to the carrier and the central portion thereof being clamped between the edges of the opening in the carrier resulting from formation of the strip, each of the loops encompassing a portion of one of the spaced parts of said foot piece, the carrier having substantially cylindrical outer surfaces adjacent each edge of each said strip, the support legs, spaced parts, and connector of each stratclier finger assembly being clamped in contacting relation with said outer surfaces by said loops.

2. The combination of kclaim 1 in which the support legs are axially aligned.

3. The combination of claim 1 in which the support legs are axially aligned and wherein the spaced parts of the foot piece are parallel.

4. rl`he combination of claim 1 in which the support legs converge in a direction opposite to the direction of projection of the scratcher fingers from the coils.

5. The combination of claim l in which the foot piece is 'offset in the same direction as the scratcher fingers, with respect to the support legs.

6. In a well bore cleaning scratcher, the combination of: a cylindrical metallic collar adapted to be mounted upon and to encircle a well pipe, a circumferential series of scratcher finger assemblies mounted upon the collar, each of the assemblies including a pair of coils, each coil having a scratcher finger projecting from one end thereof and a support leg projecting from the other end thereof, an offset foot piece joining said support legs, each foot piece having spaced parts joined by a connector, a plurality of retainers on the collar, one for each scratcher finger assembly, each retainer comprising a strip of metal sheared on two edges from the collar and deformed outward therefrom to form two loops at spaced locations, the ends of each strip remaining integrally joined to the collar and the central portion thereof being clamped between the edges of the opening in the collar resulting from formation of the strip, each of the loops encompassing a portion of one of the spaced parts of said foot piece, the collar having substantially cylindrical outer surfaces adjacent each edge of each said strip, the said support legs, spaced parts, and connector of each scratcher finger assembly being clamped in contacting relation with said outer surfaces by said loops.

7. In a well bore cleaning scratcher, the combination of: a longitudinal metallic carrier adapted to be fixed upon the outer surface of a well pipe, a longitudinal series of scratcher finger assemblies mounted upon the carrier, each of the assemblies includinfy a pair of coils, each coil having a scratcher finger projecting laterally from one end thereof and a support leg projecting from the other end thereof, an offset foot piece joining said support legs, cach foot piece having spaced parts joined by a connector, a plurality of retainers on the carrier, one `for each scratcher finger assembly, each retainer comprising a longitudinal strip of metal sheared on two edges from the carrier and deformed outward therefrom to form two loops at spaced locations, the ends of each strip remaining integrally joined to the carrier and the central portion thereof being clamped between the edges of the opening in the carrier resulting from formation of the strip, cach of the loops encompassing a portion of one of the spaced parts of said foot piece, the carrier having substantially cylindrical outer surfaces adjacent each edge of each said strip, the said support legs, spaced parts, and connector of each scratcher nger assembly `being clamped in contacting relation with said outer Vsurfaces by said loops.

8. ln a well bore cleaning scratcher, the combina tion of: a metallic carrier adapted to be mounted upon a well pipe, a series of scratcher linger assemblies mounted upon the carrier, each of the assemblies including a pair of coils, each coil having a scratcher finger projecting from one end thereof and a support leg projecting from the other end thereof, the support legs on each said assembly being symmetrically positioned with respect to said scratcher fingers, an offset foot piece joining said support legs, said foot piece, support legs, coils and scratcher fingers of each said assembly being formed of a single length of wire, each foot piece having spaced parts joined by a connector, a plurality of retainnv ers on the carrier, one for each scratcher finger assembly, each retainer comprising a strip ofmetal sheared on parallel edges from the carrier and deformed outward therefrom to form two loops at spaced locations, the ends of each strip remaining integrally joined to the carrier and the central portion thereof being clamped between the parallel edges of the opening in the carrier' resulting from formation of the strip, each of the loops encompassing a portion of one of the spaced parts of said foot piece, the carrier having substantially cylindrical outer surfaces adjacent each edge of each said strip, the said support legs, spaced parts, and connector of each scratcher finger assembly being clamped in contacting relation with said outer surfaces by said loops.

9. The combination set forth in claim 8 in which the carrier comprises a cylindrical collar adapted to encircle a well pipe, and wherein the retainer strips extend axially of the collar.

10. rfhe combination set forth in claim 8 in which the carrier comprises a longitudinal member adapted to be fixed to the outer surface of a well pipe, and wherein the retainer strips extend longitudinally of said member.

References Cited in the file of this patent UNlTED STATES PATENTS 2,881,839 Wright et al. Apr. 14, 1959 2,881,840 Wright et al. Apr. 14, 1959 FOREIGN PATENTS 1,188,046 France Mar. 9, 1959 

